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The altered peaks and troughs of the sinusoidal waveform displayed on this oscilloscope indicate the signal has been 'clipped.'

Clipping is a form of waveform distortion that occurs when an amplifier is overdriven, which happens through attempts to increase the voltage or current beyond its threshold of power. Image File history File links Merge-arrows. ... An oscilloscope screen of an amplifier clipping. ... Image File history File links Clipping_1KHz_10V_DIV_clip_A_5ohms-1-.jpg Summary Oscilloscope readout of an amplifier output. ... Image File history File links Clipping_1KHz_10V_DIV_clip_A_5ohms-1-.jpg Summary Oscilloscope readout of an amplifier output. ... In mathematics, the trigonometric functions are functions of an angle, important when studying triangles and modeling periodic phenomena. ... Illustration showing the interior of a cathode-ray tube for use in an oscilloscope. ... Waveform quite literally means the shape and form of a signal, such as a wave moving across the surface of water, or the vibration of a plucked string. ... For other uses, see Distortion (disambiguation). ... For the British rock band of the same name, see Amplifier (band). ...

Overview of clipping

When an amplifier is pushed to create a signal with more power than its power supply can produce, it will amplify the signal only up to its maximum capacity, at which point the signal will be amplified no further. As the signal simply "cuts" or "clips" at the maximum capacity of the amplifier, the signal is said to be "clipping". The extra signal which is beyond the capability of the amplifier is simply cut off, resulting in a distorted waveform.

Many electric guitar players will intentionally overdrive their guitar amplifiers to cause clipping in order to get a desired sound (see guitar distortion). An electric guitar An electric guitar is a type of guitar that uses pickups to convert the vibration of its steel-cored strings into electrical current, which is then amplified. ... For the UK magazine, see Guitarist (magazine). ... Mesa Boogie Mark IV, A guitar combo amplifier A guitar amplifier is an electronic amplifier designed for use with an electric or electronic musical instrument, such as an electric guitar. ... For other uses, see Distortion (disambiguation). ...

All amplifiers have voltage and current limits. Some amplifiers will use creative techniques to increase these limits or decrease them as needed. If an amplifier needs to output 20 V, but is limited to +10 V to -10 V, then the amplifier will output +10 V. It is best not to speak of a power limit outside of specific applications where the amplifier has an output impedance nearly equal to the load. For instance, a modern solid state amplifier may achieve maximum power output into a load that is ten times smaller than it can thermally handle over a long period of time. In electrical engineering, Impedance is a measure of opposition to a sinusoidal electric current. ...

Effects of clipping

In power amplifiers, the signal from an amplifier operating in clipping has two characteristics that could damage a connected loudspeaker: For the Marty Friedman album, see Loudspeaker (album) An inexpensive low fidelity 3. ...

• Because the clipped waveform has more area underneath it than the smaller unclipped waveform, the amplifier produces more power. This extra power can cause damage to any part of the loudspeaker, including the woofer, tweeter, or crossover, via overheating or overexcursion.
• In the frequency domain, clipping produces strong harmonics in the high-frequency range. Extra high-frequency weighting of a signal is more likely to damage a tweeter than a signal that was not clipped. However most loudspeakers are designed to handle signals with abundant high frequencies, like cymbal crashes, which have a greater high-pitch frequency weighting than amplifier clipping could produce. Therefore damage attributable to this characteristic is rare.

Other effects of clipping include: For delivered electrical power, see Electrical power industry. ... A Sony 9 inch woofer Woofer is the term for a loudspeaker driver that is designed to produce low frequency sounds, typically from around 40 hertz up to a few hundred hertz. ... A shielded Peerless v-line dome tweeter A tweeter is a driver designed to produce high frequencies, typically from around 2,000 hertz to 20,000 hertz (20,000 Hz is generally considered to be the upper limit of the human ear). ... Audio crossovers are a class of electronic filters designed specifically for use in audio applications, especially hi-fi. ... Frequency domain is a term used to describe the analysis of mathematical functions with respect to frequency. ... In acoustics and telecommunication, the harmonic of a wave is a component frequency of the signal that is an integral multiple of the fundamental frequency. ... For the Japanese rock band, see Cymbals (band). ...

• When applied to a musical signal, the clipping may prevent a note from decaying in a normal amount of time. This can cause rapidly played notes to blend together.
• Music which is clipped experiences amplitude compression, whereby all notes begin to sound equally loud as loud notes are being clipped to the same output level as softer notes.

Digital clipping

This PCM waveform is clipped between the red lines

Main article: saturation arithmetic

In digital signal processing, clipping occurs when the signal is restricted by the range of a chosen representation. For example in a system using 16-bit signed integers, 32767 is the largest positive value that can be represented, and if during processing the amplitude of the signal is doubled, sample values of 32000 should become 64000, but instead they are truncated to the maximum, 32767. Clipping is preferable to the alternative in digital systems — wrapping — which occurs if the digital hardware is allowed to "overflow", ignoring the most significant bits of the magnitude, and sometimes even the sign of the sample value, resulting in gross distortion of the signal. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... PCM is an initialism which can have different meanings: Phase Change Material Pulse-code modulation, a way to digitally encode signals representing sound and their video counterparts Potential Cancer Marker Communist Party of Mexico Plug Compatible Manufacturer Power-train control module, a computer in a car which controls the car... If the result is too large to be represented, the result is set to the largest representable number. ... Digital signal processing (DSP) is the study of signals in a digital representation and the processing methods of these signals. ... Signed-digit representation of numbers indicates that values can be prefixed with a − (minus) sign to indicate that they are negative. ... A sample refers to a value or set of values at a point in time and/or space. ... The term arithmetic overflow or simply overflow has the following meanings. ... The binary representation of decimal 149, with the MSB highlighted. ...

Avoiding clipping

As seen on the oscilloscope, the wave resulting from the clipping is not a full sine wave. To avoid this, the overall level of a mix can be lowered, or a limiter can be used to dynamically bring the levels of the loud parts down (for example, bass and snare drums). In trigonometry, an ideal sine wave is a waveform whose graph is identical to the generalized sine function y = Asin[ω(x − α)] + C, where A is the amplitude, ω is the angular frequency (2π/P where P is the wavelength), α is the phase shift, and C is the... In electronics, a limiter is a circuit that allows signals below a set value to pass unaffected, as in a Class A amplifier, and clips off the peaks of stronger signals that exceed this set value, as in a Class C amplifier. ... A bass drum is a large drum that produces a note of low definite or indefinite pitch. ... The snare drum or side drum is a tubular drum made of wood or metal with skins, or heads, stretched over the top and bottom openings, and with a set of snares (cords) stretched across the bottom head. ...

It is not simple to eliminate all clipping, as filtering can align various frequencies in such a way as to create excessive peak outputs. A high-pass filter is one type of filter that can do this. The excessive peaks may become clipped even though the amplifier can play any single sine wave without clipping. As such, some audiophiles will use amplifiers that are rated for power outputs over twice the speaker's ratings. They will then set the amplifier up with low gain, so that the amplifier does not overpower the speaker in the long run. A high-pass filter is a filter that passes high frequencies well, but attenuates (or reduces) frequencies lower than the cutoff frequency. ...

Repairing a clipped signal

Perfect restoration is of course impossible, because part of the original signal was lost. Thus, it is much preferable to avoid clipping. That being said, sometimes repair is the only option. In that case, the goal is to make up a plausible replacement for the clipped part of the signal.

There are several methods of which partial restoration can be achieved. Once the clipped portion is known, one can attempt partial recovery. One such method is interpolation or extrapolation of known samples. While this approximation is rarely close to the original, the subjective quality may be improved. For other uses, see Interpolation (disambiguation). ... In mathematics, extrapolation is the process of constructing new data points outside a discrete set of known data points. ...

Other methods may also be used. One of the methods in CuteStudio Declip, for example, works by copying the signal directly from one stereo channel to another, as it may be the case that only one channel is clipped.

Several software solutions of varying results and methods exist to counteract this problem: Sony Sound Forge, Adobe Audition, Nero Wave Editor, and a plugin in the Audacity LADSPA package come with clip restoration software. There is also a Nyquist plugin called Clipfix for Audacity. Sony Sound Forge, formerly known as Sonic Foundry Sound Forge, is a digital audio editing and creation suite aimed at the professional as well as the semi-professional market. ... Adobe Audition (formerly Cool Edit Pro) is a digital audio editor computer program from Adobe Systems featuring both a multitrack, non-destructive mix/edit environment and a destructive-approach waveform editing view. ... This article is about the audio software. ...

Sources of clipping

In analogue audio equipment, there are three general causes of clipping: An analog or analogue signal is any time continuous signal where some time varying feature of the signal is a representation of some other time varying quantity. ...

1. An integrated circuit or discrete solid state amplifier cannot give an output voltage larger than the voltage it is powered by (commonly a 24- or 30-volt spread for operational amplifiers used in line level equipment).
2. If the power supply capacitor is no longer able to keep the voltage "flat" due to a massive current draw, the positive and negative voltage supply of the amplifier will fluctuate resulting in sort of a clipped signal (AC line frequency harmonics).
3. A vacuum tube can only move a limited number of electrons in an amount of time, dependent on its size, temperature, and metals.
4. A transformer (most commonly used between stages in tube equipment) will clip when its ferromagnetic core becomes electromagnetically saturated.
5. While less common, an amplifier can limit the current output for a variety of reasons both intentional or not. The result of this form of clipping may not create a flat top to the Voltage wavefrom, but rather a flat top to the current waveform.
6. Certain signal processing elements can produce a unique form of phase-inverted clipping when the input signal exceeds the common-mode input range of an opamp. The result is that the voltage waveform clips, but in the wrong direction. This form of clipping should be limited to DIY electronics.

Some audiophiles believe that the clipping behavior of vacuum tubes is superior to that of transistors, in that vacuum tubes clip more gradually than transistors, resulting in harmonic distortion that is generally less objectionable. Integrated circuit of Atmel Diopsis 740 System on Chip showing memory blocks, logic and input/output pads around the periphery Microchips with a transparent window, showing the integrated circuit inside. ... In physics, the solid state is one of the three phases of matter (solid, liquid, and gas). ... A wall wart style variable DC power supply with its cover removed. ... Structure of a vacuum tube diode Structure of a vacuum tube triode In electronics, a vacuum tube, electron tube, or (outside North America) thermionic valve or just valve, is a device used to amplify, switch or modify a signal by controlling the movement of electrons in an evacuated space. ... Properties The electron (also called negatron, commonly represented as e−) is a subatomic particle. ... Ferromagnetism is a phenomenon by which a material can exhibit a spontaneous magnetization, and is one of the strongest forms of magnetism. ... An audiophile, most generally, is a lover of sound or music, but the word is more commonly used about someone who cares about hi-fi playback of sound recordings, rather than live performances. ... Structure of a vacuum tube diode Structure of a vacuum tube triode In electronics, a vacuum tube, electron tube, or (outside North America) thermionic valve or just valve, is a device used to amplify, switch or modify a signal by controlling the movement of electrons in an evacuated space. ... Photo of transistor types (tape measure marked in centimeters) Transistor in the SMD form factor The transistor is a solid state semiconductor device used for amplification and switching. ...

Length clipping

The term clipping may also refer to the shortening of voice snippets due to failures in voice activity detection equipment. It is unrelated to amplifier saturation. Voice activity detection or voice activity detector is an algorithm used in speech processing wherein, the presence or absence of human speech is detected from the audio samples. ...

See also

• Loudness war
• Valve sound
• Clipper
• Overdrive (music)
• Dynamic range compression